.bridge{width:100%;height:45px;background-image:url(/train-animation/bridge.svg);background-repeat:repeat-x;background-position:0 0;position:relative;left:50%;transform:translate(-50%);z-index:1;margin:50px 0 20px}.train{width:180px;height:21px;position:absolute;top:0;right:0;z-index:3;animation:moveRightToLeft 7s linear infinite;-moz-animation:moveRightToLeft 7s linear infinite;-webkit-animation:moveRightToLeft 7s linear infinite}@keyframes moveRightToLeft{0%{right:-180px}to{right:calc(100% + 180px)}}